It takes three years minimum for a fighter pilot to get to your first fleet squadron unless all of the stars align, but less than 2.5 years is unheard of- slightly faster for Air Force since they don't have to land on carriers. Many pilots are 4 years post-commissioning before they show up. Sure, you can speed it up during war, but that doesn't pan out so well. They could do it in WWII because 1) they had to and 2)flying jets is harder.
Source - I was a tactics instructor, test pilot, and flight instructor in jet aviation.